wolf359 schrieb:Die Abstrahlung der Restwärme erfolgt mit einem gebündelten Infrarotstrahl auf der erdabgewandten Seite des Raumschiffs, und natürlich wäre das Raumschiff durch die Erwärmung der Sonne "sichtbar", aber mit einigen Modifikationen vielleicht auch nicht mehr, als ein kleiner Asteroid, von denen es eine Unmenge gibt,
Na die Orbitalmechanik macht es doch leicht schwer immer der Erde abgewand zu bleiben. Mal abgeshen davon das dein Strahl eigentlich ein IR Laser sein muss.
Besides, redirecting the emissions merely relocates the problem. The energy's got to go somewhere, and for a fairly modest investment in picket ships or sensor drones, the enemy can pretty much block you from safely radiating to any significant portion of the sky.
And if you try to focus the emissions into some very narrow cone you know to be safe, you run into the problem that the radiator area for a given power is inversely proportional to the fraction of the sky illuminated. With proportionate increase in both the heat leakage through the back surfaces, and the signature to active or semi-active (reflected sunlight) sensors.
Plus, there's the problem of how you know what a safe direction to radiate is in the first place. You seem to be simultaneously arguing for stealthy spaceships and complete knowledge of the position of enemy sensor platforms. If stealth works, you can't expect to know where the enemy has all of his sensors, so you can't know what is a safe direction to radiate. Which means you can't expect to achieve practical stealth using that mechanism in the first place.
Sixty degrees has been suggested here as a reasonably "narrow" cone to hide one's emissions in. As a sixty-degree cone is roughly one-tenth of a full sphere, a couple dozen pickets or drones are enough to cover the full sky so that there is no safe direction to radiate even if you know where they all are. The possiblility of hidden sensor platforms, and especially hidden, moving sensor platforms, is just icing on the cake.
Note, in particular, that a moving sensor platform doesn't have to be within your emission cone at any specific time to detect you, it just has to pass through that cone at some time during the course of the pre-battle maneuvering. Which rather substantially increases the probability of detection even for very narrow emission cones.
(Somebody suggested using a continuous blinding barrage of nearby nuclear detonations in order to hide thrusting.)
The timescale of the radiant emission from a nuclear detonation in vacuum is measured in milliseconds. The recovery time of a good CCD array is measured in microseconds. You'll need to detonate nuclear explosives at a hundred hertz, minimum, to cover an accelerating ship. That's going to get expensive.
It also rather clearly indicates where the enemy should start looking...
wolf359 schrieb: die alle noch nicht entdeckt wurden. Ein unauffälliger Asteroid bekommt bei Sichtung nur eine "Nummer" und das war's, ein kleines Objekt mit einer unnatürlich hohen Wärmeabgabe bekommt schnell die geballte Aufmerksamkeit der Astronomen, der Öffentlichkeit und anderer "Interessenten"...
Selbst einfache Lebenserhaltung erzeugt schon unheimliche Differenzen.